Gas burner



May 11,1943. BAKER' 2,318,985

I I as BURNER- 1 Filed Nov. 23, 1940 WIT/156556.

Patented May 11, 1943 UNITED STATES PATENT OFFICE GAS BURNER Charles 1.Baker, West Hickory, Pa. Application November 23, 1940, Serial No.366,870 3 Claims. (01. 158- 116) This invention relates to gas burners,and more v particularly to burners used with automaticgas water heatershaving copper coil heating surfaces and generally known as instantaneousheaters.

Gas burners of this character are generally made in two main parts, aBunsen mixer tube and a flame-spreading member at the upper end of thetube. Also, a copper gauze is generally used as a flame check to preventthe flame from flashing back into the mixer tube. These burners areprovided with aplurality of outlet burner ports which are disposed closetogether to insure ignition from port to port after the gas in the portadjacent the pilot light has been ignited. Due to the proximity of theports to one another, the burning gas streams issuing from them mergetogether and form a sheet-like flame. As sheet flames are difilcult toquickly aerate, they are long and increase in length with an increase inthe fuel rate. At times of high gas rate the sheet flame may extend farup into the heating coil where the burning gases are cooled, thusresulting in incomplete combustion,-considerable carbon monoxide in theflue gases, and deposits of. carbon over the heating surfaces. In somecases of high gas rate the gas issuing from the burner ports does notignite until it is several inches above the spreader. This again isobjectionable for the reasons just given. The copper gauze, so generallyused with this type of gas burner, frequently becomes choked with dustaccumulations and other foreign matter and thereby reduces the quantityof primary air to such an extent as to cause low temperature,lengthened, soot-depositing flames. The flame spreader becomes very hot,and this heat during long operating periods is destructive to the castiron of which the spreader is made. In most automatic gas water heatersthe burners must be positioned so as to face in certain directions. Thisrequires special care or understanding of combustion conditions whenplacing such a burner in a water heater, and also frequently requirespositioning members to keep the burner in its correct position. I

It.is among the objects of this invention to provide a gas burner forinstantaneous water heaters and the like which avoids the formation ofsheet flames, which permits ready ignition from port to port, whichoperates emciently at all fuel rates, which does not require coppergauze'or the like to prevent flash back into the mixer tube, whichpreheats the fuel, which can be readily positioned in a water heaterwithout the use of special positioning members or special understandingof the burner, which burns the fuel close to the spreader, and in whichthe spreader member does not become overheated. The preferred embodimentof the invention is illustrated in the accompanying drawing in whichFig. 1 is a side view of my gas .bum'er partly broken away to show thespreader member in elevation; Fig. 2 is a vertical section through theburner taken on the line II--II- of Fig. l; and Fig. 3 is a horizontalsection taken on the line III-III of Fig. l.

Referringto the drawing, amixer tube l for gas and air is provided inits lower end with a cross member 2 having a central vertical opening 3therethrough adapted to receive a gas nozzle, not shown, connected to'agas supply line. The open spaces 4 (Fig. 1) between the cross member andthe wall of the tube permit primary air to be drawn into the tube andmix with the gas to form the proper combustible fuel mixture. Disposedin the upper portion of the mixer tube, which is preferably cylindrical,is a flamespreading member 6 that projects above the tube. The major orlower portion of the spreader is preferably cylindrical and is machinedto seat snugly in the upper end of the tube.

The periphery of the spreader is provided with a plurality of laterallyor circumferentially spaced vertical recesses or grooves I extendingsubstantially from top to bottom of the spreader and forming with thetube separate outlet burner ports. .The portions of the spreader betweenthese grooves therefore take'theform of vertical ribs 8, and, inaccordance with this invention, at least their exposed upper portionsare wide enough to prevent the streams of fuel issuing from the upperends of the ports from mingling and thereby producing a sheet flame. Inother words, each port maintains its own separate flame.

As the ports are thus too far apart to permit pilot-light ignition atone port from traveling to plished by. extending the upper portion ofthe spreader, including the upper portions of the ribs, outwardly acrossthe top of the mixer tube at a predetermined distance above it. By-passopenings 9 are thus formed between the top of the tube side wall and thebottom of these overhanging portions of the ribs. The laterally extendedupper portions or the ribs also serve, by projecting outwardly abruptlyover thetop oi the tube to maintain the flames separated and to preventany tendency sheet flame. To assure the by-passes being of the correctsize, means is provided for limitin the distance that the spreader canbe'inserted in the mixer tube. This is preferably done by having thelaterally extendedupper portion of one of the ribs longer than theothers so that its lower end engages the top of the tube and serves as astop ll.

The lower portions of the ribs which engage the side wall of the mixertube are relatively long in order to provide narrow ports which are longenough to prevent flash-back without the use of copper gauze. Thespreader and its ribs extend so far down into the cool incoming gas inthe tube that the ribs serve as cooling flns for the bodyof the spreaderto keep it from overheating. In thus cooling the spreader, the ribstransfer heat to the incoming gas and preheat it, which is highlydesirable. The portion of the spreading member within the mixer tube ispreferably hollow, as shown in Fig. 2.

The top of the spreader extends out over the periphery of the tube sothat condensate dripping from, the heater coils can not enter the burnerports.

According to the provisions of the patent statutes, I have explained theprinciple and construction of my invention and have illustrated anddescribed what I now consider to represent its best embodiments.However, I desire to have it understood that, within the scope of theappended claims, the invention may be practiced otherwise than asspecifically illustrated and described.

I claim:

1. A gas burner comprising an upright mixer tube for gaseous fuel, anda'flame spreader disposed in the upper end of the tube and projectingabove it, the side of the spreader being provided with a plurality oflaterally spaced ribs extending from substantially the top of theoithemtouniteintoa;

spreader to a point inside of the tube to thereby i'o'rm apluralityotseparate burner ports, and said ribs having extension'portionsprojecting outwardly across the top of the tube at a pre- 'determineddistance above it to form with the top oi the tube-ignition by-passesfrom one of said ports to another, said outwardly projecting portions ofthe ribs creating separate burner flames above the by-passes and beingwide enough to maintain the flames separated above the burner.

2. A flame spreader adapted to be seated in the upper end of a mixertube for gaseous fuel and to project above it, the side of the spreaderbeing provided with a plurality of laterally spaced ribs extendingdownwardly from substantially the top of the spreader to form aplurality of separate burner ports, and the upper portions of said ribshaving lateral extensions all but one of which are adapted to projectoutwardly across the top of the tube at a predetermined distance aboveit to form ignition by-passes, and said one extension having adownwardly projecting portion adapted to rest on top of the mixer tube,said lateral extensions creating separate burner flames and being wideenough to maintain the flames separated above the spreader.

3. A gas burner comprising an upright mixer tube for gaseous fuel, aflame spreader seated in the upper end of the tube and projecting aboveit, said spreader having a body portion surrounded by a plurality oflaterally spaced ribs extending substantially from its top down into thetube to form with the tube a plurality of separate burner ports, and theexposed upper portions of said ribs having lateral extensions projectingoutwardly across the top of the tube, whereby separate burner flames arecreated, said extensions being wide enough to maintain the flamesseparated above the burner, all but one of said extensions being spaceda short distance above the tube to form ignition by-passes between theports, and said one extension resting on top of the tube to control theheight of said bypasses.

CHARLES I. BAKER.

